Search

We attempted to improve the solubility of poorly water-soluble drugs by preparing drug-loaded polyvinyl alcohol (PVA) nanofibers as a solid dispersion system via emulsion electrospinning. Probucol (PBC), a poorly water-soluble drug, was used as a model drug. Nanofibers were electrospun using an oil/water (o/w) emulsion consisting of PBC dissolved in an immiscible solvent, such as ethyl acetate, and an aqueous PVA phase. PBC-containing PVA nanofibers with diameters ranging from 300 to 600 nm were obtained by electrospinning from o/w emulsions. The physical properties of the nanofibers were affected by the degrees of polymerization and hydrolysis of the PVA grades. In PVA nanofibers prepared without a surfactant, PBC existed in an amorphous state, and the dissolution of PBC was greatly improved. PBC dissolution was lower in PVA nanofibers with 30% PBC content compared to those with 11% or 20% PBC. In PVA nanofibers prepared using the surfactant P80 as an emulsifier, PBC was partially crystallized; however, the PBC was homogenously dispersed, and dissolution was improved, even in PVA nanofibers containing 30% PBC. PVA nanofibers produced by o/w emulsion electrospinning were demonstrated to be suitable solid dispersion systems enabling robust controlled release of poorly water-soluble drugs.

In order to relieve pain due to oral mucositis, we attempted to develop mucoadhesive microparticles containing indomethacin (IM) and gel preparations with IM microparticles that can be applied to the oral cavity. The mucoadhesive microparticles were prepared with a simple composition consisting of IM and polyvinyl alcohol (PVA). Two kinds of PVA with different block properties were used, and microparticles were prepared by heating-filtration and mixing-drying. From the X-ray powder diffraction patterns, differential scanning calorimetry thermograms, and morphological features of the IM microparticles, IM should exist as polymorphic forms in the microparticles. Rapid drug release properties were observed in the IM microparticles. Increased drug retention was observed in IM microparticles containing PVA, and the IM-NK(50) gel, using a common block character PVA and heating-filtration, showed good long-term drug retention properties. In vivo experiments showing significantly higher drug concentrations in the oral mucosa were observed with IM microparticles prepared by heating-filtration, and the IM-NK(50) gel maintained significantly higher drug concentrations in the oral mucosa. From these results, the IM-NK(50) gel may be useful as a preparation for relieving oral mucositis pain.